Packaging apparatus

Abstract

A packaging apparatus for folding the front and rear ends of a tubular film which covers an article toward the bottom surface of the article. After the front end of the film has been folded while the article is transported, a bar-like roller traveling along the bottom surface of the article at a higher speed than the transport speed of the article catches the rear end of the film and folds it. An air blowing device is installed along the path of travel of the bar-like roller. The air from the air blowing device presses the front and rear film ends against the bottom surface of the article. Thereby the front and rear film ends are prevented from being contacted by the bar-like roller which would strip it from the bottom surface of the article.

What is claimed is: 
     
       1. A packaging apparatus comprising: means for transporting a plurality of articles to be packaged which are covered with a tubular film so that they are spaced from each other,   means for cutting the tubular film between adjacent articles to form a film end which is disposed forwardly as viewed in the transport direction and a film end which is disposed rearwardly as viewed in the transport direction for each article,   means for pulling both film ends respectively by air currents toward the bottom of the article,   fixed wall means adapted to engage the front film end to fold said front film end onto the bottom of the article by the force with which the article is transported,   bar-like roller means adapted to move along the bottom surface of the article at a higher speed than the transport speed of the articles, thereby catching the rear film end to fold the latter onto the bottom side of the article, and   means extending along the path of travel of said bar-like roller means and designed to blow air to urge the front and rear film ends against the bottom surface of the article.   
     
     
       2. A packaging apparatus as set forth in claim 1, wherein: said bar-like roller means comprises a plurality of bar-like rollers included in an endless chain traveling body,   said chain traveling body has a pair of endless chains disposed along the path of transport of the articles and capable of traveling in the direction of transport,   said chain traveling body carries said plurality of bar-like rollers between the endless chains with said rollers spaced from each other,   at least one of the spacings between said bar-like rollers is larger than the others so as to define an opening,   said packaging apparatus has a vacuum suction passage surrounded by said chain traveling body and having a suction port which opens to the path of transport of the articles, and   said chain traveling body is capable of intermittently traveling and stopping at a position where said opening is aligned with said suction port.   
     
     
       3. A packaging apparatus as set forth in claim 2, including: a first air reservoir installed along the path of travel of the chain traveling body and within the chain traveling body and supplied with compressed air, and   a plurality of first air outlet holes which are formed in said first air reservoir and through which the compressed air in the first air reservoir is blown through the spacings between adjacent bar-like rollers toward the bottom of the article.   
     
     
       4. A packaging apparatus as set forth in claim 2, including: a lid member capable of blocking the suction port in said vacuum suction passage,   a second air reservoir formed in the interior of said lid member and fed with compressed air, and   a plurality of second air outlet holes formed in said lid member and designed so that when said lid member blocks said suction port, the holes direct air through the spacings between adjacent bar-like rollers toward the bottom surface of the article.   
     
     
       5. A packaging apparatus as set forth in claim 4, including: conduit means for feeding compressed air to the lid member,   an on-off valve placed in said conduit means,   means for opening and closing said lid member, and   means operatively connected to said opening and closing means for closing said valve when the lid member is opened and opening said valve when the lid member is closed.   
     
     
       6. A packaging apparatus as set forth in claim 1, including: a pair of roller means designed so that when the tubular film is cut by the tubular film cutting means, said pair of roller means nip a region of the film adjacent the front film end at the article positioned upstream of the cut point as viewed in the transport direction,   at least one of said rollers being rotated in the direction associated with the direction of transport of the article so that by pulling said film end by said rollers, contraction of the film at said article is prevented and so is occurrence of wrinkles in said film.   
     
     
       7. A packaging apparatus as set forth in claim 6, wherein: the cutting means comprises a fixed cutter, a cutter receiver movable toward and away from said cutter and adapted, when approaching said cutter, to cut the tubular film, and means for moving said cutter receiver toward and away from the cutter, and   one of the roller means is movable together with said cutter receiver toward and away from the other roller, said one roller means nipping the film between said one roller means and the other roller means when approaching the other roller means.   
     
     
       8. A packaging apparatus as set forth in claim 7, including: a stroke absorbing elastic body disposed between said one roller means and said cutter receiver for making greater the stroke of said cutter receiver than the stroke of said one roller means,   wherein when the film is cut, even after the film has been nipped between the roller means, the cutter receiver can be moved toward the cutter, and it is only after the cutter receiver has been moved a predetermined distance away from the cutter upon the cutting of the film that said one roller means is moved away from the other roller means.   
     
     
       9. A packaging apparatus as set forth in claim 6, wherein both roller means are capable of nipping the film at a position corresponding to the bottom of the article. 
     
     
       10. A packaging apparatus as set forth in claim 7, including: a vacuum suction passage having a suction port for producing an air current for pulling the front end of the film of the article toward the bottom side of the article,   said other roller means is disposed to extend along the edge of the suction port in said vacuum suction passage.